What are the reasons for the slow dissolution of cationic polyacrylamide?
Cationic polyacrylamide is a water-soluble polymer or polyelectrolyte, because its molecular chain contains a certain number of polar groups, it can be adsorbed by the water suspended solids, so that the inter-particle bridge or by charge and So that the particles condensed to form a large floc, so it can accelerate the sedimentation of particles in the suspension, there is a very clear solution to clarify the solution to promote filtration and other effects.
1. the proliferation of molecules
The dissolution process of matter is that the solute molecules are much larger in size than the solvent molecules, so the diffusion rate of the two is very different. In the initial stage of the dissolution, only the water molecules are diffused unilaterally to the cationic polyacrylamide, and the cationic polyacrylamide molecules are not May spread to the direction of water, so the first swelling is the necessary stage of dissolution.
2. Hydrogen bonds and entanglement
In the molecular chain of the cationic polyacrylamide and the molecular chain, the hydrogen bond between the amide side groups can form hydrogen bonds, the hydrogen bond is the strongest intermolecular force, and the high molecular weight cationic polyacrylamide molecular chain has a large amount of hydrogen bonds; At the same time, high molecular weight cationic polyacrylamide molecular chain is very long, long molecular chain is bound to curl, they are also together together entangled together. Therefore, if the cationic polyacrylamide accelerates the dissolution of the solvent water molecules need to rely on the rapid infiltration and attack, net hydrogen bond dissociation and molecular chain entanglement. The dissolution rate of the imported cationic polyacrylamide is related to its molecular weight, ionic degree, molecular geometry, dissolution temperature, stirring and feeding mode.